Which of the following is not a mechanism by which lightning causes injury?

Lightening tends to cause injury by pushing the compressed air before the current but not in front of the current as mentioned in the option. This effect is called the 'sledge hammer blow' effect of Lightening as described by Spencer. Spencer formulated four mechanisms "Lightning" by which it does its effects on humans and the surroundings. They are: 1. Direct effect from the high voltage electric current discharge that passes to the eah. 2. Surface flash burning effect from the super heated air discharge. 3. The air is expanded and repelled - the mechanical effect brought about from the force of displaced air is exhibited around the flash. 4. Compression effect due to the movement of air pushed before the current - Sledge hammer blow effect. Ref: The Essentials of Forensic Medicine and Toxicology By Dr. K. S. Narayan Reddy, 27th Edition, Pages 295-296; Concise Textbook Of Forensic Medicine and Toxicology By Sharma, 2nd Edition, Page 73.